A report by Jim Lee of the National Weather Service has the answer. He found that statistics from the State Climatologist Office show snow has fallen in May in 59 of the last 125 years, but it has only occurred in five of the last 20 years.

The last measurable May snow reported in Iowa fell on May 1-2, 2005 with traces across about the northern third of the state, 0.1 inches at Stanley and 0.3 inches at Cresco.

Most of the measurable snowfall events happened in the late 1800s and the first half of the 20th century.

The five events producing the highest May snowfall in Iowa:

1. In 1882, snow fell on May 12 (across southeastern Iowa, with about an inch at Iowa City) and then again on May 23. On the latter date about the southeastern quarter of Iowa received snowfall, with around half an inch at Des Moines and up to 4-6” at Washington.

2. In 1907, spring was very cold and backward at least partially due to the large eruption of the volcano Ksudach in eastern Russia. Snow fell across all of Iowa (and the Midwest) on May 3, with amounts ranging up to 1.2” at Des Moines and 1.5” at Atlantic and Corning. Another statewide snow fell on May 15 that was light in most areas but amounted to 5” at Rock Rapids.

3. In 1945, snow fell across about the northwestern half of Iowa on May 9-10 with most of the area reporting measurable snowfall. Amounts ranged up to an amazing 8” at Denison.

4. In 1947, one of the most remarkable weather events in Iowa history occurred when snow fell across most of the state on May 28, with measurable snow across the north and west ranging up to an incredible 10” at Le Mars. This is the latest spring snowfall on record in Iowa and also the highest amount ever recorded in the month of May.

5. In 1967, snow fell across about the southern half of Iowa on May 3, with amounts ranging up to an amazing 8” at Glenwood.